QDev Seminar: Luka Trifunovic

High-efficiency resonant amplification of weak magnetic fields for single spin magnetometry at room temperature

We demonstrate theoretically that by placing a ferromagnetic particle between a nitrogen-vacancy (NV) magnetometer and a target spin, the magnetometer sensitivity is improved dramatically. Namely, using materials and techniques already experimentally available, our proposed setup is sensitive enough to detect a single nuclear spin within ten milliseconds of data acquisition at room temperature. The obtained sensitivity is practically unchanged as long as the ferromagnet surface to the target spin separation is smaller than the ferromagnet lateral dimensions which is typically about a tenth of a micron. When used for NV ensemble measurements, our scheme benefits from ensembles with many NVs since the sensitivity is further enhanced by three orders of magnitude. Our proposal opens the door for nanoscale NMR on biological material under ambient conditions.